Lance Armstrong in Fifth Place after Prologue

Lance Armstrong split with former teammate and rival Alberto Contador, yet that hasn't made the seven-time Tour de France champion any more comfortable.

Luxembourg event is also Armstrong's first race since his former U.S. Postal teammate Floyd Landis admitted doping throughout his career and alleged that Armstrong and several other elite American riders were involved, too.

On Wednesday, Armstrong finished the 1.66-mile prologue in fifth place, with a time of 3 minutes, 51 seconds. Jimmy Engoulvent of France, who finished 10 seconds ahead of Armstrong, took the race leader's jersey.

"It was obviously short, fast, not my specialty but when you had to accelerate, when we had to use true power, absolute power, I felt like I had that," Armstrong said.

The first real stage Thursday is a 112-mile ride from Luxembourg to Hesperange.